Haematological emergencies Flashcards
Does neutropenic sepsis always present with febrile neutropenia?
No
Patient can have neutropenia without fever
What are the 2 defining features of neutropenic sepsis?
Absolute neutrophil count is 0.5 x 10(9)/L or lower
Temperature greater than 38 degrees Celsius OR any symptoms/signs of sepsis
What is the main reason why neutropenic sepsis is a life-threatening emergency?
Neutropenic patients already have weakened immune system and are more likely to contract bacterial infections which can become disseminated and fatal
Give 4 haematological risk factors for neutropenic sepsis?
Recent chemotherapy (usually within 14 days): Biggest risk factor
Immunotherapy with cytotoxic drugs
Stem cell transplant patient
Bone marrow disorders
What treatment pathway is used for neutropenic sepsis?
Sepsis 6 care bundle
How does a patient with neutropenic sepsis start the sepsis 6 care bundle treatment?
Call 999 ambulance for emergency transfer to hospital, ideally within 1 hour of neutropenic sepsis recognition
What is included in the sepsis 6 care bundle, to treat neutropenic sepsis?
3 diagnostic and 3 therapeutic steps delivered within 1 hour after initial recognition of sepsis
- Oxygen administration
- Two sets of blood cultures
- Venous blood lactate
- Fluid resuscitation
- Appropriate antibiotics
- Monitor observations
How should oxygen be administered to treat neutropenic sepsis?
Give oxygen therapy to people with reduced oxygen saturation (below 92%) or with an increase in oxygen requirement over baseline, to maintain oxygen saturation above 94% unless contraindicated
How are the two blood cultures taken from the patient, in neutropenic sepsis treatment?
Paired cultures from a peripheral/central line in situ and periphery
What is the first line antibiotic for neutropenic sepsis and why?
Continuous IV piperacillin with tazobactam (tazocin)
Provides anti-pseudomonal cover
What hormone drug can you administer to patients with neutropenic sepsis and why?
Recombinant G-CSF eg. Filgastrim
Can be used as treatment and prophylaxis to prevent neutropenia
If a patient with neutropenic sepsis is allergic to penicillin, which antibiotic should be administered instead of tazocin?
Second-line: IV Meropenem
Tazocin contains penicillin so cannot be used
What are the 4 emergency sickle cell crises?
Vaso-occlusive crisis
Aplastic crisis
Sequestration
Acute chest syndrome
What is a vaso-occlusive crisis in SCD patients?
Sickled RBCs get stuck in microcirculation eg. capillaries and cause ischemic injury to organs and tissue
What is an aplastic crisis in SCD patients?
Bone marrow suppression usually due to infection of parvovirus B19 which stops RBC production for a short time
What is acute splenic sequestration crisis in SCD patients?
Sickled RBCs block blood vessels exiting spleen, so spleen becomes engorged with blood
Causes severe anaemia and life-threatening circulatory collapse
What is acute chest syndrome in SCD patients?
Vaso-occlusive crisis in pulmonary vasculature
What is the main symptom of sickle cell crises?
Sudden and intense pain throughout whole body
What is the management for sickle cell crisis (HOP to it)?
H: Hemodilution (IVF, PRBCs)
O: Oxygen supplementation
P: Pain relief
In sickle cell crisis, how is hemodilution managed in 2 steps?
Exchange transfusion: Machine replaces sickled blood with donor PRBCs
Intravenous fluids: Slows sickling process
In sickle cell crisis, how is oxygen supplementation managed?
Provide oxygen if below 95% on room air
In sickle cell crisis, how is pain relief managed?
Mild pain: Paracetamol/ibuprofen/naproxen
Moderate pain: Codeine, tramadol
Severe pain: Morphine, oxycodone
What are the 3 defining signs of acute chest syndrome in SCD patients?
Fever
Respiratory symptoms
Pulmonary infiltrate (opacity) on chest x-ray
What is TTP and why is it a haematological emergency?
Clots form in microcirculation which blocks blood flow to heart, kidney, brain and other organs
What is the classic pentad of TTP symptoms? (FAT RN)
Fever
Anaemic symptoms due to MAHA
Thrombocytopenia: Purpura or bleeding
Renal failure: Thirst, frequent urination
Neurological symptoms
Which 5 investigations should be immediately done to confirm TTP?
FBC: Marked thrombocytopenia, haemolytic
anaemia markers eg. reticulocytosis, low LDH, low haptoglobins
Coagulation screen: Normal
Peripheral blood film: Schistocytes, polychromasia, thrombocytopenia
ADAMTS13 level: Very low
Urinalysis and renal function tests
What is the mainstay emergency treatment of TTP, whether it is congenital or immune-mediated?
Plasma exchange: Donor plasma with normal ADAMS13 levels replaces patient’s plasma which contains autoantibodies and no ADAMS13
Which 3 medications can either be administered to treat TTP?
Steroids eg. methylprednisolone: Reduces antibody level and immune response to ADAMS13
Rituximab: Stops ADAMS13 from being broken down
Caplacizumab: Stops platelets from sticking to von Willebrand factor
Which supportive medicines are administered to treat TTP?
Folic acid
Omeprazole
Dalteparin (heparin injection)
What is Tumour Lysis Syndrome (TLS)?
Tumour cell breakdown (usually caused by cancer treatment) release contents into bloodstream
Give 4 common risk factors for TLS?
High-grade cancers eg. Burkitt’s lymphoma, acute leukaemias
Recent chemotherapy
Renal issues
Dehydration
Conditions causing hyperuricemia
What is the classic tetrad of lab findings for TLS? (LUCK)
L: LDH low
U: Hyperuricemia
C: Hypocalcemia
K: Hyperkalemia
What are some symptoms of TLS?
Urinary symptoms eg. haematuria, dysuria
Hypocalcemia: Cramps, vomiting, altered mental status, spasms
Hyperkalemia: Weakness, paralysis
Arrythmias, sudden death
How do you manage TLS?
Hyperuricemia: Rasburicase, if condraindicated give allopurinol
Hyperphosphatemia: IV fluids and monitor high urine output, if uncontrolled use dialysis
Hypocalcemia: Cardiac monitoring unless symptomatic, then give calcium gluconate
Hyperkalemia: Cardiac monitoring unless severe, then haemodialysis
What is Acute Promyelocytic Leukaemia (APML)?
Rare subtype of AML characterised by over proliferation of promyelocytes
Why is APML a haematological emergency?
Causes coagulopathy which can lead to CNS and pulmonary haemorrhaging
Why does APML cause coagulopathy in 2 ways?
APML blasts express tissue factor and secrete IL-1, which activate clotting cascade
Cancer Procoagulant in present in APML cells and activates factor 10 directly
Give 5 risk factors of APML?
Age: Risk increases as age increases (more common in middle age than children)
Hispanic
Obesity
Occupational exposure eg. Chemical agents
Previous chemotherapy or radiotherapy
Give common signs and symptoms of APML?
Petechiae
Excessive mucocutaneous bleeding
Frequent infections and fever
Fatigue
Weight loss and appetite loss
Pain in joints and bones
Pallor
Which 5 lab tests should be done to investigate APML?
FBC: Pancytopenia
Coagulation screen: High APTT and high PT
D-dimer test: High
Blood film
FISH genetic testing
What is the characteristic finding of APML on a blood film?
Large, bi-lobed, hypergranular cells (buttock cells) with multiple auer rods
When APML is suspected, what genetic testing must be done for rapid diagnosis?
FISH: PML-RARA fusion gene
Translocation between chromosomes 15 and 17 produces PML-RARA fusion gene
RARA codes for retinoid acid receptor alpha, which normally allows promyelocytes to differentiate: Fusion gene prevents this
What is the emergency management of APML?
All-trans retinoic acid (ATRA)
Arsenic trioxide
What is DIC?
Disseminated intravascular coagulation
Hypercoagulable state causes microvascular and macrovascular clotting, which then depletes platelets and causes bleeding
What are the causes of DIC?
STOP Making Trouble
S: Sepsis/snakebites
T: Trauma (acute traumatic coagulopathy)
O: Obstetric complications
P: Pancreatitis or liver disease
M: Malignancy
T: Transfusions
What are the signs and symptoms of DIC?
Petechiae, purpura, bruising
Uncontrollable bleeding from many sites
Hypotensive
Confusion
SOB
What lab tests confirm DIC?
FBC: Thrombocytopenia
Coagulation screen: Prolonged PT, APTT, TT
Low fibrinogen level
Elevated D-dimer
Blood film: Schistocytes
What is the general treatment pathway of DIC?
Treat acute symptoms eg. major bleeding
Treat underlying cause
How do you treat active bleeding in DIC?
No anticoagulants
Transfuse platelets and fibrinogen or FFP
How do you treat DIC with no major bleeds?
Low dose anticoagulant eg. LMWH
Transfuse platelets, fibrinogen or FFP after assessing levels
How do you treat DIC with over thromboembolism?
Therapeutic LMWH
